The key difference with the Raspberry Pi 5 is that it now uses the RP1 Peripheral Controller. The first 28 GPIO on the RP1 is dedicated to the 40-pin header and matches nearly the same or similar functionality as on the previous Raspberry Pi. You can read more about the RP1 Peripheral Controller here: RP1 Datasheet - Peripheral Controller Datasheet Draft
The key difference with the Raspberry Pi 5 is that it now uses the RP1 Peripheral Controller. The first 28 GPIO on the RP1 is dedicated to the 40-pin header and matches nearly the same or similar functionality as on the previous Raspberry Pi. You can read more about the RP1 Peripheral Controller here: RP1 Datasheet - Peripheral Controller Datasheet Draft
